Sweet cherry varieties can be crudely classified into two groups: traditional English, and modern. The traditional English varieties are in fact mostly of central European origin (and have very un-English names) but were the mainstay of cherry orchards in Kent for the first half of the 20th century or earlier. These varieties are typified by good traditional cherry flavours, but are not particularly easy to grow and often have complicated pollination requirements.
Modern cherry development is now an international affair but was started by the Summerland research station in British Columbia, Canada in the 1940s. The original objective was to tackle the horticultural problems associated with commercial cherry production, particularly fruit-splitting and pollination. The most famous of these new varieties is Stella but there are many others (often starting with an "S"-sound, such as Sweetheart, Sunburst, and Celeste). Whilst they lack the tradition and romance associated with the older English varieties, the flavours are still excellent and their self-fertility and easier horticultural characteristics make them a much better choice for the gardener with space for only one or two cherry trees.